Abstract: A balancing method for balancing a flexible rotor is disclosed. First, the rotor is rotated and vibration of the rotor is measured to determine resonance speeds. Vibration exciting forces of frequencies synchronized with the rotor rotation in two orthogonal directions are imparted to the rotor or rotor support bearings while rotating the rotor at a speed near the respective resonance speeds. The amplitude and the phase of the vibration exciting force which reduces the resonance vibration of the rotor are then determined. A correction weight on the basis of the amplitude and the phase of the vibration exciting force is then determined. Balancing work on the rotor such as grinding of the rotor or addition of a mass to the rotor in accordance with the correction weight is then carried out, followed by a rotor rotation conducted for the purpose of confirming the effect of the balancing work.

Abstract: A process determines the unbalance of a driven rotating rigid rotor with respect to at least one compensation plane of the rigid rotor according to relative position and size. The unbalance effect is determined in that the position and size of the oscillations caused by an unbalance in the subcritical range in at least one segment of a rotation of the rigid rotor are determined at least twice on at least one support of the rigid rotor. The time intervals between the individual determinations during at least one segment of the rotation are taken into account, and the change of the dynamic effect due to the acceleration is taken into account during at least one segment of the rotation.

Abstract: A wheel balancer has a spindle for mounting a wheel/tire assembly thereon, a motor for spinning the spindle about its longitudinal axis, and at least two sensors for sensing imbalance forces. A set of calibration coefficients for the wheel balancer are determined solely from the measurements made during a set of calibration spins and from knowledge of the amount of imbalance mounted to the rotating spindle during the calibration spins, without any knowledge or measurement of the relative geometry of the balancer. The set of calibration coefficients and other calibration data is stored in an electronic memory for subsequent use in balancing a wheel/tire assembly. During balancing, a wheel/tire assembly mounted on the spindle is spun and the corresponding output signals of the sensors are measured and recorded.

Abstract: A method of manufacturing tires comprising the steps of: constructing a sample set of tires; measuring at least two parameters of each tire of the sample to obtain first and second measurement data; measuring force variations of each tire of the sample set during a rotation test at a select rotation rate to obtain force variation data; determining transfer functions between the first and second measurement data and the force variation data; constructing a set of production tires; measuring the two parameters of the production tires; predicting force variations of the production tires at the select rotation rate based on the transfer functions and the two measured parameters of the production tires; responsive to the predicted force variations, comparing the production tires to predetermined criteria; and controlling manufacture of the tires responsive to the comparison.

Abstract: The invention provides a tire changing and balancing machine. On the same shaft used to mount and demount a tire, a wheel assembly is balanced. A tire on a wheel assembly is placed between a breaker blade and a breaker pad. The breaker blade collapses the tire. The wheel assembly is then mounted on a shaft. A mounting and demounting head is used to remove the tire from the wheel assembly. A new tire is placed on the wheel assembly. The mounting and demounting head is then used to mount the new tire on the wheel assembly. The wheel assembly and mounted tire are then spun on the shaft and balanced.

Abstract: The invention provides a wheel balancer with a filtering system that reduces signal noise using a phase shift and subtraction circuit. In addition the inventive wheel balancer utilizes an automated parameter entry device, and a fast data refresh system which reduces the burden on the central processing unit CPU.

Abstract: A test weight for use with a counterbalanced motor for a compressor assembly, for example, including a body having an opening formed in it and sized to engage the outer diameter of an external eccentrically positioned ball bearing of the counterbalanced motor. A plurality of cantilevered spring fingers are integrally formed with the body along the opening in the test weight for spring gripping the external ball bearing. A plurality of centering pads formed on the fingers hold the center of mass of the test weight close to the center of mass of the ball bearing. In the preferred embodiment, stop tabs project from the centering pads to provide a positive stop upon contact with the outer race of the ball bearing. A method of testing a motor employs the test weight which is attached to the ball bearing to reproduce the application load requirements for the motor, and permits testing of the motor independently of the application.

Abstract: Balancing a wheel and tire assembly includes sensing imbalance of a wheel and tire assembly and determining therefrom the magnitude and placement of at least one correction weight to correct the imbalance. The magnitude of the correction weight is compensated to correct for curvature of actual correction weights. The compensated magnitude is displayed to the user. If the weight amount or placement spot is inconvenient for the user, the user can initiate a split weight procedure which determines a pair of weight magnitudes and weight placements which are vectorially equivalent to the corresponding single correction weight in terms of correcting imbalance. The pair of weight magnitudes are reverse compensated for curvature to calculate the effective weights thereof and the weight placements are calculated based upon the effective weights.

Abstract: A balancing station includes a vertical spindle having a collet for frictionally engaging the center hole of a wheel. A motor driven drum is mounted on an arm which is moved by an actuator to urge the drum against the wheel with a radial force so that it can frictionally drive the wheel. An idler drum or a second driven drum mounted on a similar arm on the opposite side of the wheel is moved by an actuator to engage the wheel at a location diametrically opposite the driven drum to apply a radial force to the wheel equal and opposite to the force from the driven drum. The arms are symmetrically mounted with respect to the spindle so that the two drums will contact diametrically opposite locations on the wheel for any size wheel over a large size range.

Abstract: Wheel balancer design informs the user to apply correction weight(s) on one or two planes of the wheel tire assembly. A comprehensive combination of a "split weight" key and display usage allows the user to split a singular weight into a variety of choices involving two (or more) weights. The two weights are applied at the proper angular displacements so as to provide perfect imbalance correction using standard size incremental weights.

Abstract: An electronic wheel balancer apparatus includes an operator interface which adapts the device for concurrent use by multiple operators. A microprocessor works in conjunction with internal memory units to save and retrieve data associated with each operator for use by the processor when a selected operator is actively in control of the balancer.

Abstract: The unbalance of a body (10) to be balanced is indicated in a polar co-ordinate system (52) on a screen (50) of a cathode ray tube (48) by means of a first visible mark (60). The body (10) to be balanced may be rotated by a drive motor (20) by means of a belt (22). A pulse generator (30), producing trains of pulses that are relatively phase displaced by a quarter of a period, is coupled to the drive motor (20). A computer (34) generates a position-indicating signal from the pulse trains, and a reference signal is produced by a reference mark on the body (10) to be balanced and obtained from a pick-up device (28). A position-indicating radial finger (68), which is a second visible mark and rotates on the screen (50) in phase locked manner with the body (10) to be balanced, is obtained from the position-indicating signal. When the position-indicating radial finger (68) coincides with the first visible mark (60), the unbalanced body (10) is positioned in the desired working position.

Abstract: The present invention discloses a wheel balancer having a floor standing base and an operator keyboard and display pod mounted to a support above the base. Manually adjustable brackets attaching the substantially L-shaped support to the base and to the pod allow the pod to be adjusted by the operator through four degrees of freedom, including into a space minimizing position for shipping or storage.

Abstract: The invention provides a wheel balancer that is able to determine if its measurements are accurate. The invention takes a set of measurements and determines if the measurements are sufficiently consistent. If they are sufficiently close the invention uses the measurements to calculate wheel imbalance. If the measurements are not sufficiently close the invention uses the measurements to calculate wheel imbalance. If the measurements are not sufficiently close the invention rejects at least one data point and collects more measurements until either the invention yields sufficiently close data points or the machine is stopped. A display is provided for diagnostic messages.

Abstract: A system is disclosed for assembling and balancing automotive wheels. Each wheel includes a wheel rim having a valve stem opening and a tire adapted to be mounted on the rim. The circumferential position and magnitude of any tire imbalance is marked on the tire. A plurality of valve stems is also provided wherein the valve stems vary in weight from each other. The tire is positioned with respect to the rim so that the valve stem opening is substantially diametrically opposed to the circumferential position of the tire imbalance and a valve stem having a weight substantially the same as the magnitude of the tire imbalance is then positioned in the valve stem opening. The tire is then inflated thus completing the assembly and balancing of the tire.

Abstract: A method for balancing a rotor of an alternator in a diesel-electric locomotive in which the rotor is drivingly coupled to a power output shaft of a diesel engine. A speed sensor and a vibration sensor are coupled to the rotor for providing output signals representative of instantaneous rotational velocity and instantaneous amplitude of vibrational motion of the rotor, respectively. In the inventive method, the rotor is accelerated to a first preselected rotational velocity and a first rotor unbalance is determined from the velocity and vibration signals. The rotor is then accelerated to a second preselected rotational velocity and a second rotor unbalance is determined. The first and the second rotor unbalance determinations are combined to identify a first correction weight and position thereof for minimizing the first and the second rotor unbalance. The identified weight is installed and the process repeated until the unbalance is corrected such that vibration is less than a preselected maximum value.

Abstract: A process and device providing automatic identification of increased resonance response during a balancing procedure on permanently calibrated, hard-bearing balancing machines. Unbalance values are determined for each bearing plane of a rotor being balanced for at least three measuring speeds. At least two difference values of speed-related adjacent unbalance values are determined in an evaluation device. Increased resonance response is determined if the difference values between adjacent higher measuring speeds are proportionally greater than those between adjacent lower rotational speeds.

Abstract: In an apparatus for retarding the measuring spindle of a balancing machine after a measuring run in which the measuring spindle is brought up to the measuring speed of rotation by means of a hand crank, the measuring spindle is retarded by the co-operation of first and second brake discs, one of which is non-rotatably connected to the measuring spindle while the second rotates with the measuring spindle during the measuring run but is held in a stationary position relative to the frame structure of the machine in the retardation phase. The second brake disc is arrested upon termination of the measuring run by a holding pin which is actuated to engage an engagement location on the second brake disc, in dependence on the angular position and the speed of rotation thereof, to provide controlled arresting of the brake disc.

Abstract: A bearing construction having an annular clearance provided between the outer surface of a rotary shaft of a rotatable object and the inner wall of a bearing assembly and a fluid feeding means for filling the clearance with a fluid to form a layer of the fluid. A shaft displacement detecting means detects a displacement of the rotary shaft during a rotating action.

Abstract: In a method and an apparatus for balancing a grinding wheel, balancing weights on the grinding wheel remain secured to the grinding wheel in an unbalance measuring operation, and the positions at which the balancing weights are secured to the grinding wheel are stored. In a repositioning operation for compensating for measured unbalance of the grinding wheel, the influences of the forces of the balancing weights during the unbalance measuring operation are derived from the stored positions of the weights and compensated for so as to balance the ginding wheel.

Abstract: In a method and apparatus for improving the fit of a pneumatic tire on a motor vehicle wheel rim, before a wheel balancing operation is carried out the wheel is accelerated to a maximum permissible peripheral speed and centrifugal force acting at the wheel is measured at that speed. The drive for the wheel with tire thereon is stopped when the measured variation in centrifugal force reaches or falls below a predetermined limit value.

Abstract: The invention provides an improved unbalance measuring machine wherein the drive member for imparting rotational forces to the workpiece has two distinct positions of engagement with the workpiece. A first position is used to maintain minimal contact with the workpiece and maintain a steady-state rotation of the workpiece. A second position is used to impart additional rotational forces to the workpiece for the purposes of accelerating, decelerating and indexing the workpiece.

Abstract: The mass of a tire/wheel assembly is altered to apply a static imbalance to the assembly in a manner which reduces the overall tendency of the assembly to cause vibration in the plane perpendicular to its axis of rotation when in use. The applied imbalance, combined with any static imbalance initially inherent in the tire/wheel assembly, results in a desired net static imbalance oriented so as to induce a centrifugal force which opposes, and therefore tends to cancel, at least one component, such as the first order harmonic, of radial force variation characterizing the assembly. The magnitude of the net static imbalance is limited and is preferably selected to substantially equal the lesser of either: (a) a predetermined maximum limit, or (b) the amount of static imbalance required to generate at a designated highway speed a centrifugal force whose magnitude substantially equals that of the aforementioned radial force variation component.

Abstract: A low-speed balancing method is provided for balancing a rotor to introduce balance corrections for reducing unbalance due to operation of the rotor at or near critical speeds without actually balancing the rotor at such critical speeds. The method is applicable for balancing a rotor in three, four or more correction planes by utilizing combinations of generic unbalance distributions of the rotor and predetermined mode shapes of the rotor at critical speeds. A simple method is presented which allows an operator using a low-speed balancing machine to determine measured corrections applicable to two planes of the rotor and then the operator effects at least a third correction to the rotor which is proportional to the measured corrections and the unbalance/mode shape combination. The operator then repeats the low-speed balancing sequence to determine final corrections at the two planes, which are then made for finally balancing the rotor.

Abstract: The present invention relates to an unbalance point positioning method and an apparatus therefor, which carry out a positioning operation with high precision and within a short time by using, as a trigger, an unbalance phase signal due to revolution of an unbalance point of a measured object, and effecting deceleration control through feedback control with a voltage corresponding to a rotational frequency of the measured object.The apparatus includes means for rotating the object at a high speed and for determining the amount as well as the angular position of the unbalance of the object. Once the angular position is determined, this information is used to trigger a predetermined deceleration signal, which smoothly and continuously decelerates the measured object until the object is stopped with the unbalance point at a preselected position. A gradual deceleration curve, generated using a resistor and capacitor circuit, is used to minimize slippage between the rotating object and the drive mechanism.

Abstract: A method and apparatus for correcting the unbalance of a rotatable object wherein the apparatus learns from past errors and automatically adjusts to improve future unbalance corrections of the object. The object is rotated a first time and the amount and angular location of unbalance is detected and recorded. The object is than corrected for this measured unbalance and the corrected object is rotated again. The amount and angle of any remaining unbalance is detected. Then the first detected unbalance is combined with the unbalance detected in the corrected object to obtain a correction quantity which can be used when later correcting said object. The invention can be used on objects which have two separate planes of unbalance to correct the unbalance in both planes. The invention can also correct for any errors caused by any inaccuracies in the plane separation process.

Abstract: A force sensing apparatus and method in a vehicle wheel balancer is disclosed which in one embodiment includes use of a voltage controlled oscillator connected to drive a piezoelectric crystal at an oscillation frequency which is compared in phase to a frequency generated by the wheel balancer spin shaft encoder. When unbalance force imposed changes occur in the crystal oscillation frequency, an unbalance output is provided by the comparison which contains the unbalance force magnitude and angular orientation information. The unbalance output is processed to provide operator indications for facilitating application of counterweights to the vehicle wheel.

Abstract: The invention is a method and a master machine of carrying out the method, for balancing and correct a workpiece at a single station. The correction apparatus is a material applicator and ultraviolet light source which is controlled by a microprocessor to supply metered amounts of viscous material to a workpiece at a desired location to cure an unbalance. The ultraviolet light source cures the viscous material into a solid deposit.

Abstract: Dynamic wheel balancing is achieved at low (1-3 RPS) rotating velocity by mounting the wheel for rotation on a frame which is pivotally supported for any rotation caused by wheel unbalance. A transducer senses any frame movement and electrical signals corresponding to the maximum amplitude is produced by the transducer which signals are converted to indications of the amount of weight needed to balance the wheel and the location thereof.

Abstract: A wheel balancer comprises apparatus for determining the radius of a rim of a hub of a wheel and for determining the distance of the inner and outer side walls of the hub from a reference plane. A framework which is pivotal downwardly over the wheel to be balanced carries a pair of ultrasonic transducers to determine distance of the sides of the wheel from the reference plane. A transducer monitors the position of the framework. The distances monitored by the ultrasonic transducers are stored in a microprocessor against the corresponding positions of the framework at intervals on movement of the framework. The ultrasonic transducers detect a large change in distance from the reference plane caused by the hub well periphery. The hub rim radius is computed from the well periphery radius, while the distances of the side wall from the reference plane is obtained by looking up the stored values of distances which corresponds with the appropriate position of the framework for the hub rim radius.

Abstract: In a method and an apparatus for balancing successive rotary members, an unbalance measuring operation is carried out in one or more planes on each rotary member which is rotated at a measuring speed in a measuring run within an overall unbalance measuring time for ascertaining the required number of items of measuring information in a plurality of repetitive measuring cycles. After the elapse of a fraction of the overall unbalance measuring time the unbalance measuring operation is interrupted for an interruption time for the purposes of permitting the performance of working operations which due to vibration caused thereby could result in falsification of the unbalance measurement results, then unbalance measurement is resumed, and further interrupted, and so on in a repetitive procedure to make up the overall measurement time.

Abstract: A process and an apparatus for the input of parameters of a rotary member to be balanced, such as a vehicle wheel, into an evaluation unit of a balancing machine in which a rotary member to be balanced is mounted on a main shaft and the respective rotary angular positions of the main shaft are monitored in angular steps by means of an angle sensor, and reproduced. For input of the parameters of a rotary member requiring balancing, the main shaft is rotated and signal produced by the angle sensor in the rotary movement of the main shaft is used to alter the respective value of the parameter being displayed, with the main shaft being rotated until the desired value in respect of the parameter in question is displayed.

Abstract: The invention described here provides a method for obtaining the "best" solution to balancing engine vibration where one or more corrective weights are applied to accessible stage of an engine, while other unbalanced stages remain inaccessible, and hence, no balancing weights can be applied there. The method involves placing balancing weights at accessible stages only, but taking into account vibration at such stages which is created by unbalances at the inaccessible stages. The method is practiced by calculating the angular limits for placing a corrective weight onto an engine stage, followed by calculating the minimum and maximum weight magnitude to be placed on the stage so that overall engine vibration remains below a certain desired level (D). Thereafter, the optimum weight and angular position is determined by minimizing D via a procedure of incremental calculations.

Abstract: A manual parameter input system for automotive test equipment such as a vehicle wheel balancer. Variable pressure input knobs supply rotation direction and "applied pressure" information to the balancer's internal computer. The computer updates the value displayed by digital visual displays at a rate corresponding to the applied pressure to the knob. The visual display output is independent of the actual rotational position of the input knobs, and hence is highly tolerant of mechanical slippage and other mechanical deficiencies in the input system.

Abstract: A method and an apparatus for balancing a rotor, in which compensation points are distributed symmetrically on the rotor's circumference about the axis of the rotation, which compensation points are suitable for an imbalance compensation by means of a component revolving with the rotor and on its circumference having scannable structural elements, pulses are generated that provide information for the respective rotational angle position of the rotor for determining the imbalance angular position and for indexing the rotor after the imbalance measuring run into the compensation angle position, and this component may be embodied as a gear wheel or fan wheel.

Abstract: A measured object support mechanism for use in an unbalance measuring apparatus for detecting vibrations resulting from rotation of a measured object supported by a measured object supporting member and measuring an unbalance of the measured object. This support mechanism comprises a slidable supporting device disposed between a base block supporting the unbalance measuring apparatus and the measured object supporting member.

Abstract: For a body rotating on an axis and having a moment of inertia relative to the axis, an apparatus for dynamically suppressing unwanted rotational phenomena occurring relative to the axis of rotation, i.e., phenomena which exhibit themselves in a body only when the body is rotating about the axis, such as, dynamic imbalance and resonance at critical rotational speeds. One or more inertial masses are movably affixed to the body such that they can be selectively moved radially and circumferentially with respect to the axis. Appropriately placed sensors, such as strain gauges, accelerometers, vibration transducers, and the like detect the phenomena and pass pertinent parameters of the phenomena to a controller, preferably a computer, which analyzes the parameters to determine, among other things, the magnitudes of the phenomena.

Abstract: A shaft synchronous balancing apparatus wherein a rotor to be balanced is rotated in conjunction with appropriate balance plane located transducers and a non-contacting shaft monitoring pick-up, for example of an optical variety. The latter pick-up derives a one times per revolution reference signal which is treated by a software driven process control system including dual timer-counters to evaluate the period of revolution, T, and to develop N incremental sampling pulses having a duration or time constant of T/N. Preferably, N is an even integer power of 2. Periodic updating of the duration of a time constant is developed utilizing only one software interrupt in conjunction with the two counter timers. A nulling technique for canceling offset at the signal treatment stages is provided which accommodates for the high amplification levels necessary at the front end of the system.

Abstract: The apparatus uses an influence coefficient calculating method to allow a rotor supported on active magnetic bearings to rotate about an inertial axis which, due to possible imbalances in the rotor, may be different from the geometric axis of the rotor, without transmitting imbalance forces to the housing of the active magnetic bearings.

Abstract: An apparatus for measuring unbalance on a rotary member such as a motor vehicle wheel comprises a drive motor for driving a main shaft carrying the rotary member, by way of a reduction transmission means having a self-locking action so that the main shaft can be braked by the self-locking action after an unbalance measuring run. The self-locking action of the reduction transmission means also serves to resist a rotary moment applied to the main shaft when tightening or loosening a clamping arrangement with which the rotary member is clamped on the main shaft, so that the main shaft remains in a stationary position during that operation.

Abstract: The present invention provides for a method of generating an electronic bobweight signal used to offset an unbalance signal before the unbalance signal is received at the input portion of the electronic circuitry of the unbalance detection system. The electronic bobweight signal and unbalance signal are matched in their phase angle and are each sampled a specified number of equally spaced times per revolution of the workpiece to provide accurate bobweighted unbalance data without the need for use of physical bobweights and their inherent disadvantages.

Abstract: A method and apparatus for balancing rotatable members whereby a member to be balanced is rotated first in one direction about an axis at a selected speed and then is rotated in the opposite direction about the same axis and at the same speed. A sensor determines the circumferential apparent location of greatest imbalance or runout of the member in each of the directions of rotation, following which any imbalance of the rotatable member is compensated for by adding or removing weight to or from such member at a circumferential zone which is equidistant between the apparent locations of greatest imbalance.

Abstract: A mounting stand in a balancing machine mounting assembly includes a stationary mounting block and a mount for a rotary member to be balanced. The mount is supported on the mounting block by two parallel springs capable of oscillating movement in a mounting plane in the measurement direction. The mounting stand further has at least one measurement value pick-up sensor operatively disposed between the mounting block and the oscillatable mount for detecting oscillation of the mount produced by an out-of-balance rotary member and to supply corresponding measurement signals. A rotatable adjusting unbalance weight of a known magnitude is mounted to the oscillatable mount and can be selectively brought into operation to cause oscillatory movement of the oscillatable system, to perform a calibration.

Abstract: Dynamic wheel balancing is achieved at low (1-3 RPS) rotating velocity by mounting the wheel for rotation on a frame which is pivotally supported for any rotation caused by wheel unbalance. A transducer senses any frame movement and electrical signals corresponding to the maximum amplitude is produced by the transducer which signals are converted to indications of the amount of weight needed to balance the wheel and the location thereof.

Abstract: A measured object support mechanism for use in an unbalance measuring apparatus for detecting vibrations resulting from rotation of a measured object supported by a measured object supporting member and measuring an unbalance of the measured object. This support mechanism comprises a slidable supporting device disposed between a base block supporting the unbalance measuring apparatus and the measured object supporting member. The support mechanism further comprises a second slidable supporting device disposed between the base block and a dummy weight in order to detect external vibrations.

Abstract: A control arrangement for controlling the power supplied to an electric motor connected to a rotary member to drive same in rotation by way of a belt drive, to accelerate the rotary member to a given speed and to brake it in a slip-free manner provides that a signal which is proportional to the speed of rotation of the rotary member is compared to a signal which is proportional to the speed of rotation of the motor. The supply of power to the electric motor is correspondingly controlled in dependence on the result of the comparison operation.

Abstract: An apparatus for measuring imbalance of rotors, in particular motor vehicle wheels, having a primary shaft driven by an electric motor. The rotor to be tested is secured to the primary shaft with the aid of a clamping device, which transmits the drive torque transmitted to the primary shaft to the rotor by means of friction. The apparatus includes a time-controlled brake, which when the electric motor is switched on reduces the drive torque in a time-controlled manner until the rush moment fades. As a result, loosening of the clamping device is prevented and a gentle start is assured.

Abstract: A mounting apparatus for mounting a rotary member such as a motor vehicle wheel to a drive shaft of an unbalance measuring arrangement includes a stationary measuring spindle for rotatably carrying the rotary member bearings which are part of the rotary member itself. An entrainment hub which can be drivingly coupled to the drive shaft of the unbalance measuring apparatus supports the measuring spindle rotatably relative thereto, and engages the rotary member to drive it in rotation. The measuring spindle is prevented from rotating with the entrainment hub by a restraining device.

Abstract: A method and apparatus for the measuring of the imbalance and the calculation of the location and size of the necessary weights to be added to a rotating object to balance it. Included are a mounting surface for receiving the object and a shaft affixed to and extending away therefrom with the shaft supported at two spaced apart points therealong, and a pair of pressure sensors with one each at the two support points of the shaft for providing a signal that is proportional to the force exerted by the shaft at the corresponding one of the support points as the object is rotated. In addition, a position and speed of rotation detection means is affixed to the shaft to continuously provide speed of rotation and position data of the shaft. Also there is a pair of tracking filters, each disposed to receive the output signal from a different one of the pair of pressure sensors with the center frequency of both filters being substantially the speed of rotation of the shaft.

Abstract: A method and device to determine the relative reference position for an angle measurement of an object within an angle scale covering the round angle of the entire rotation of the object and divided into several angle areas of equal size on an exposed target area on or attached to the object of which an illuminated orbit is scanned. A significant deviation of the beam characteristics at least one point on the orbit forms a reference signal, which is coupled to the angle value of an angle scale to determine the reference angle position on the object.